48 



If the results of Dr. Munch on the cause* of susceptibility and 

 immunity of forest trees lo disease should prove true in the case 

 of this disease, also, we may hope to be able to control the bark 

 disease in shade, lawn, and park trees, by keeping up the water 

 .content of the tree. 



Whether nursery stock serves to introduce the disease Into 

 new localities is an important problem to be determined by ob- 

 servation and experiment. The present method of inspection 

 and cutting out would be inefficient if the fungus lives commonly 

 as a saprophyte at the base of the tree on dead bark and can at- 

 tain a parasitic habit with some slight change in weather condi- 

 tions. If, on the other hand, it exists only as a wound parasite, 

 then inspections would be possible and the cutting out method 

 effective. However, with such problems as these undecided, no 

 one can pronounce definite judgment upon the efficiency of the 

 cutting out method. Once however, these facts are established, 

 modifications may be made in the present method by which its 

 effectiveness may be insured at possibly a lower cost than can 

 now be expected. 



The present method which the Pennsylvania Commission has 

 adopted of eradicating only spots where the fungus is distinctly 

 parasitic, can accomplish a great good in a sanitary way, and 

 once sufficient facts are forthcoming, the method may be altered 

 to suit our knowledge and thus its efficiency assured. 



THE CHAIRMAN : The next paper, entitled "Recent Notes on 

 the Chestnut Bark Disease,'' will be delivered by Professor H. R. 

 Fulton, Division of Pathology, Pennsylvania State College. 



RECENT NOTES ON THE CHESTNUT BARK DISEASE. 



BY PROFESSOR H. R. FULTON, Pennsylvania State College, HI ate 



College, Pa. 



The steady and devastating spread of the chestnut bark dis- 

 ease brings us face to face with a grave situation, and raises 

 many questions of great importance. Most of these will centre 

 about the three great questions : Is it possible to check effectively 



